Financial details of the transaction were not disclosed. Funds for the transaction came from the Carlyle Equity Fund II, a $2.4 billion fund that invests in middle-market companies.

Kathleen McCann will remain chief executive and chairman of United Road, while Mark Anderson will remain president and chief operating officer. The rest of the current management team will remain in place, according to the firm.

United Road expects to move 3.5 million vehicles this year compared to the 1.5 million the company moved in 2012, when the company was acquired by Charlesbank, McCann said.

"Our strategic growth platform was really turbocharged in late 2012 when we were acquired by Charlesbank," McCann said. "They provided the capital, support and encouragement to expand our reach and capabilities — both organically and through the acquisition of a major competitor, which gave us a deeper presence in the southeast and southwest U.S."

In late 2013, United Road acquired the auto transport division of Waggoners Trucking, which made the company the second-largest car hauler in the North America.

Mary Petrovich, a Carlyle operating executive and chairwoman of AxleTech International, will join the United Road board.

United Road and Charlesbank were represented by RBC Capital Markets and William Blair in this transaction. Carlyle was advised by Kirkland & Ellis as legal counsel and Ernst & Young as financial advisor.

Operations

An increasing number of flood-damaged vehicles are returning to the used market across the country, and increasingly in states where flooding might not be top of mind, according to new data from Carfax.

To increase dealer confidence in purchasing decisions within the wholesale used-vehicle marketplace, Manheim is introducing flat-rate pricing for automatic post-sale inspections, providing dealers a hassle-free way to reduce their risks and help ensure vehicles bought at auction are in the expected condition.